In the last few years, the amount of cable in use has increased significantly. Especially in the area of computers and telecommunication devices, there has been a large increase due to the development of new devices and technologies such as new telephone systems, local area networks, and so forth.
These systems often need miles of electric cable in order to interconnect devices located far apart. Such cables are needed to connect, for example, a master control unit, such as a switch or a telephone system, with outlets or the like spread over one or more buildings of a large campus.
Frequently, racks carrying hundreds of connectors are arranged in a single room. In order to be able to find a particular connector within this jumble, the cable ends are normally marked. If this is not the case, a cable must be trailed from one end to the other, which is generally very cumbersome.
For marking cables, the following methods are used today:    Installation of marking rings carrying letters or numbers    Installation of a labeled heat-shrinkable sleeve    Fastening of plastic slips.
U.S. Pat. No. 4,579,759 discloses the use of an inscribable cable marking strip comprising a strip of an adhesive tape having a self-adhering bottom side and carrying an inscribable marking section. The beginning of the inscribable marking section is located at a distance from the adjacent front end of the adhesive tape to define an unlettered, transparent starting section of the strip which may be pressed onto the cable without soiling the marking section or smudging the lettering applied to it.
Several other cable marking systems are known, for instance using codes preprinted on the sleeve or printed on labels glued onto the sleeve, and the like. A cable marking system is also known wherein ring-shaped marking elements are introduced in a recess on the outside of the support.
However, such systems have the disadvantage that they are either very costly or time consuming, or that tapes, rings, and the like may slip or fall off, so that the marking is no longer discernible.
Therefore, it has been proposed to mark the cable itself. For example, U.S. Pat. No. 4,370,542 describes a method for marking an identification at pre-selected intervals along a length of cable by a laser marking device. However, it is still difficult to find such a marked cable when mounted to a connector and arranged among a multitude of other cables.
It is therefore an object of the present invention to provide a device for identification marking of cables that is easy to handle and allows easy location of a particular cable among others.
It is still another object of the present invention to provide a method for identification marking of such cables that allows marking without the use of additional equipment.